All Questions
Tagged with electromagnetism forces
103
questions with no upvoted or accepted answers
4
votes
0
answers
785
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Lorentz force on superconductor vortices
I am reading a paper on superconductivity and in it it says that the vortices are subject to a Lorentz force given by $$\vec{F}_L=\frac{\Phi_0\vec{I} \times \vec{H}}{cH}$$ Here $\vec{F}_L$ is the ...
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3
votes
4
answers
87
views
Is the Lorentz force applied to bulk objects?
Assume that a bulk uniformly charged ($+Q$) nonconductive sphere is set in motion inside a uniform magnetic field. Is it correct to claim that the trajectory of the bulk sphere inside the magnetic ...
- 2,503
2
votes
0
answers
22
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What are the conditions according to which the levitation force between a magnet and a superconducting material tends to zero?
According to this article, for a disk-like superconductor and a magnet, if the radius of the superconductor tends to zero or the radius of the magnet tends to infinity, it seems that the levitation ...
- 2,503
2
votes
1
answer
175
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Does the charge distribution of two uniformly charged conducting spheres change as we bring them near each other?
Assume that we have positively charged two solid conducting spheres of the same radius and material. It is evident that the surface charge is uniform on them to eliminate the internal electric field ...
- 2,503
2
votes
1
answer
167
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Are there any relativistic corrections to electrostatic attraction between two charges moving close to the speed of light?
If two opposite charges are moving at a velocity of $0.9c$ relative to a laboratory, but are at rest relative to each other (say the charges are moving in parallel), will there be any relativistic ...
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2
votes
1
answer
153
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On the infinite range of the electromagnetic force
I am curious as to whether there is a fundamental reason why weak and strong nuclear forces have such a short range whereas gravity and the electromagnetic force seem to have infinite range.
Since ...
- 1,638
2
votes
1
answer
207
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Why is the force on an image charge the same as the force on the object it replaces?
Consider the arrangement of a point charge $q$ situated a distance $a$ from the center of a grounded conducting sphere of radius R (Griffith 4 th Ed. Example 2 or here). We find that we can replace ...
- 602
2
votes
0
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155
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Reason for repulsion of like charges
Like charges repel and unlike attract. Like magnetic poles repel and unlike attract. Since electricity and magnetism are fundamentally linked , is this attraction/repulsion due to the magnetic fields ...
- 43
2
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0
answers
402
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Odd experiment results (electromagnetics)
Okay, a bit of background. So I'm working on a linear accelerator (you might know it as a Gauss rifle), and I had worked through the equations I thought I needed (Magnetic force, displacement, etc.)
...
- 1,340
2
votes
0
answers
117
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Consistency of equation with special relativity?
The following is the equation which, I want to know, if it is valid in relativistic domain. Consider two equal charges moving in same direction with velocity $v$ and charge $q$ at a separation of $d$....
- 3,148
2
votes
1
answer
708
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The force between two magnets?
Does anyone know how to find the attraction/repulsion force between two magnets with arbitrary shapes.
What is the general formula for this ?
Thank you in advance.
- 130
2
votes
1
answer
541
views
Lorentz force in superposition of two magnetic fields
When an electron with charge $q$ travels with velocity $v$ perpendicular to a magnetic field generated between two permanent magnets with field strength $B$ and no electric field, it experiences a ...
- 652
1
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0
answers
131
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Coilgun projectile force calculation
Please excuse me if I am completely wrong because I am a 9th grader but I hopefully am able to explain briefly about my problem. I was trying to create a function to calculate the Force of an iron ...
- 11
1
vote
0
answers
28
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Which equation is most valid for finding power dissipation in a induced magnetic pendulum system?
Considering a set up where a conducting pendulum oscillates between two permanent magnets, I want to somehow calculate the power dissipated by the magnetic braking force the magnets provide, in order ...
1
vote
1
answer
94
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Attraction/repulsion forces between two magnets
If I have two identical magnets of equal strengths producing equal repulsive forces between them, and if I replace one of the magnets with a stronger magnet (everything else remaining the same), how ...
- 11
1
vote
1
answer
35
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Getting the force somehow using magneticfield force (tesla)
First off, sorry if not everything makes sense, english isn't my first language so some scientific terms may sound weird if they're in English. For a project we are making a coil gun. So we get a ...
- 11
1
vote
1
answer
61
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The force experienced on a charge, using macroscopic quantities
Zangwill says (Zangwill, Modern Electrodynamics, 2012 edition, page 40, undersection 2.3.1, "Lorentz Averaging")
...An example is the force on the charge density $\rho$ and current
density $...
- 702
1
vote
1
answer
132
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Ratio between electric and magnetic forces
Suppose I have two beams of electrons moving at speed $v$ separated by a distance $d$. I can work out magnetic and electric forces between them...
For the magnetic force, we treat the two beams wires ...
- 2,456
1
vote
1
answer
205
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Force acting on a negative particle in a magnetic field
I have recently learned about magnetic fields and particles. The recent one I have learnt is the right hand rule. The force F acting on a negative particle is always opposite to the force we get from ...
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1
vote
0
answers
26
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Why does a magnet arranged in a magnetic accelerator propogate a wheel forward?
My question is related to an interesting video i saw on magnets. The link of the video is here https://youtu.be/iyv9GhaITNE , in this video at 1:52 of the video we see the wheel is moved forward but i ...
1
vote
1
answer
92
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Magnet A exerts an magnetic force $F_1$ on magnet B, B exerts a Reactive force $R_1$ on A, B exerts an magnetic force $F_2$ on A, is $R_1=F_2$?
Let's suppose there are 2 magnets, A and B, that are within the magnetic field of each other. Then A will exert a magnetic force on B (let's name it F1), and, due to the 3rd law of Newton, every ...
- 151
1
vote
2
answers
100
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How do we apply force on a body?
We know that force is apllied either by pushing or pulling anything.
But how do we push or pull or apply force on anything.
I imagine the object A that is pushing and another object B that is getting ...
user316791
1
vote
0
answers
28
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Lorentz force transmitted to two nodes
A straight wire of length $L$ and direction $\vec{u}$ carrying a continuous current $I$ in the presence of a magnetic field $\vec{B}$ experiences a force (Lorentz force) equal to $\vec{F} = LI \vec{u}...
1
vote
0
answers
23
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Question on thinking about an electric charge as multiple electric charges in special relativity
I understand that thinking about permanent magnets as a rotating loop of charged particles can be used to derive things like how an electric charge will be effected by the magnetic field, and to ...
- 2,001
1
vote
0
answers
37
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Does the Lorentz force change when an electric current is under a magnetic field with negative permeability?
Most applications of the Lorentz force depend on the electric current passing by a material with positive permeability, normally ferromagnetic.
How much would change were the electric current to pass ...
- 441
1
vote
0
answers
21
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Force on a moving charge in front of an infinite conducting wall
Let's say we have a charge $q$ at position $\vec{x}=(x_0,y_0,z_0)$ in front of an infinite conducting wall at $z=0$. If the charge is not moving, this problem can be easily solved by the method of ...
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1
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1
answer
37
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Can you induce motion by changing magnetic field on a body which isn't magnetic?
In this video demonstration of Lenz's law, the narrator starts with a substance which doesn't respond to the magnetic field of a bar magnet yet when he moves the bar magnet in relative motion to the ...
- 7,980
1
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0
answers
47
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Unstable Equilibrium of hinged rods
I conjured up a scenario where there are two rods free to rotate about a hinge connected by their ends by spring of spring constant $k$,both their masses are $m$ and length $l$ and mass is uniformly ...
1
vote
0
answers
27
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How can I find the potential energy and force between a steel sphere and a magnet?
I'm fine with certain simplifying assumptions being made, I currently only know high-school level physics (the simpler the better). Also, if anyone can explain the intuition behind formulae, I would ...
1
vote
0
answers
60
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What should be the equilibrium field strength in the Hall effect?
I was taught in my course and have confirmed by looking in many sources that when there are moving charges (e.g. current in a wire) which are deflected due to the Lorentz force (Hall effect), the ...
1
vote
0
answers
77
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Radiation Reaction and Acausal Acceleration
The Abraham -Lorentz formula for the radiation reaction force is $${\bf F}_{rad} {= \frac{\mu_0 q^2}{6 \pi c} {\bf \dot a}}$$ and when electric charges are moving Newtons Law for an applied force ${\...
- 3,856
1
vote
0
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32
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How fundamental electromagnetic interaction occurs in electrostatic case (say, between two resting electrons )?
Interaction between two resting charges (electrostatic case - in electrostatic field) is anyways electromagnetic (because we have only 4 fundamental interactions). Electromagnetic interaction means ...
- 255
1
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0
answers
117
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verlet/leapfrog method lorentz force application
So I ll use leapfrog/varlet algorithm to calculate the trajectory of the particle
In leapfrog method for initial values we need $v_{-1/2}$ and $x_0$. Hence I can write
$v_{-1/2}=v_0-Δt/2a_0$
$v_0$ ...
- 3,122
1
vote
0
answers
94
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Showing the force on magnetic dipole
We're given a situation where the circuit can move under the influence of a magnetic force. Now I need to show that the force on the magnetic dipole is
$$\vec{F} = (\vec{m} \nabla) \vec{B} $$
Could ...
- 187
1
vote
0
answers
117
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validity of "law of vector addition of current elements"
In several articles and books, I have read that "the magnetic force on or due to a small element of a circuit is equivalent to two or more of its component elements, provided that the current remains ...
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1
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0
answers
174
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What is a simple model to find the jump height for the Thomson's Jumping Ring experiment?
I'm trying to devise a basic formula that could give a rough estimate for the jump height reached in the Thomson's Jumping Ring experiment, as detailed here.
However, it's pretty difficult as most ...
- 11
1
vote
0
answers
22
views
Field line Direction and exerted force
Magnetic field lines of a magnetic field have different directions. What information about the force exerted on a charge will give us the direction of field lines?
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0
answers
100
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Relationship between magnetic force acted upon a diamagnetic substance and the magnetic field applied to it
I have a sample of bismuth that I have applied a measured B-field to through the use of a solenoid electromagnet. I've been trying to find a formula relating the B-field to the force that the bismuth ...
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1
vote
0
answers
121
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Determining the attraction of a magnetic bob
I have a question concerning the calculation of the attraction to a ferromagnetic material in a coupled B-field, which of $N \geq3$ equally strong cylindrical permanent magnet is produced. (...
- 13
1
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0
answers
612
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Currents and magnetic fields produce forces that affect things they're not touching?
I was doing this past paper and am a little confused by question 5) part c)ii)
I correctly calculated that the force acting on the rod due to the magnetic field is 0.016N but I can't see how this ...
- 159
1
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0
answers
1k
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Calculation of magnetic force magnitude from a parmenant magnet
I was wondering how strong a magnet should be in order to be able to horizontally attract 0.2 Kg of pure iron at a distance of 0.3 M. Since I know nothing about magnets, I started looking for ...
- 11
0
votes
1
answer
47
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What happens when both magnetic field and electric field is applied to a charged particle?
Now what exactly happens when magnetic field and electric field is applied perpendicularly? What happens when they are not perpendicular?
In the question, it says that a magnetic field and electric ...
- 91
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0
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16
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What is the physical meaning of the torque term involving the magnetic displacement force?
In Zangwill's Modern Electrodynamics the magnetic torque is derived in Eq. 12.63 to be
\begin{equation}
\mathbf{N}(\mathbf{r}_0) = \mathbf{m} \times \mathbf{B}(\mathbf{r}_0) + \mathbf{r}_0 \times \...
0
votes
0
answers
23
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Is there a ponderomotive force due to a traveling wave?
Imagine a traveling, EM wave passing through some plasma. The waveform is given by the vector potential:
$A = (0, -\frac{cE_0}{\omega_0}\cos\eta, 0)$
where $\eta = \omega_0t-k_0x$ is the phase. From ...
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votes
2
answers
39
views
How great is the net force exerted on a superconducting material of a small size being subjected to an external uniform magnetic field?
Assume that we have a very tiny spherical or disk-like superconducting material that is subjected to an externally uniform magnetic field. I want to know if the net force that accelerates the ...
- 2,503
0
votes
0
answers
21
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Maximum force of a metal ball going trough coil
I've been trying to figure out the maximum force of a metal ball going trough a coil.
I have:
$$ m=\chi_m V B \qquad B=N \mu_0 I R^2 \frac{1}{2(x^2+R^2)^{3/2}} $$
Also that $F=(m\cdot B)'$. However, ...
- 103
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votes
0
answers
60
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Linear Addition of Forces for an Electromagnet design
If I have an electromagnet, designed as below(based off an Inrunner BLDC motor), and want to apply 20N of force to the magnet, would I be correct in saying each protrusion(coil and core pair) only ...
- 13
0
votes
0
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26
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Where does force act in two parallel current carrying conductors?
F=ILB.so consider length as 5 m and I as 2 ampere and B as 5 T.so the force is 50 N.does this 50 N act at one point or equally applied on full length like pressure.So what does force/length in this ...
- 1
0
votes
2
answers
69
views
Can the following set up be used to propel something upwards?
Let A and B be solenoids with the same pole facing each other.
Then will their repulsion cause the set up to jump upwards?
Please correct me if I am wrong:
Solenoid A exerts a downward force on ...
0
votes
0
answers
56
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Poincaré inverse square law unification
A while back, I came across a claim that was something like this: Poincaré said that no two fundamental force laws could have the same mathematical form such as $1/R^2$; that no two fundamental force ...
- 1